1. Field of the Invention
The present invention relates to means for the extermination of undesirable insects and particularly refers to an automatic trap for catching cockroach.
2. Description of the Prior Art
It is well know that there are a lot of pesticides and insecticides that fail in extermining the insect species for which they have been developed. This is because the insects, and particularly cockroach, are becoming more resistant to these compounds and no lethal effects are caused by many products now in the market. As a consecuence of this, new and more powerful insecticides are developed and higher risks of damages for humans are being increased.
Other systems consist of cardboards with a bait and adhesives so as to attract the insect and leading it to a surface wherein the insect is caused to get stuck in the adhesive. Frequently the cockroach gets rid of the stuck and runs away.
3. Summary of the Invention
In virtue of the above problems the inventor has studied the different cockroach species as well as their behavior, allways taking into account that no insecticides should be used to preserve the human life. When studying several possibilities, the inventor discarded a mechanical device the operation of which could depend upon parameters such as the size, volume or weight of the cockroach because of the enormous differences between the species. For example, a new device should catch with the same efficiency species like the Periplaneta orientalis with a size of 35 mm. and the breeds or babies of the Blatella germanica the size of which is 2 mm.
It is therefore an object of the invention to provide an automatic trap for catching cockroach wherein the insect is catched independently of it size, volume or weight and the insect has access, free of obstacles, to a zone adjacent to a bait wherein the cockroach is detected by a sensor capable of activating an electromechanical mechanism. To facilitate handling thereof, the device has no wires and is electrically fed by conventional batteries.
It is further an object of the invention to provide a trap for cockroach wherein the insect is detected because of the water contained in the body thereof, like in all living organisms, animal or vegetal species. The invention takes advantage of the electrical conductivity of the water to close a circuit through the insect's body and a current passing through the body of the cockroach is amplified by an amplifier to operate an electromechanical system. The amplifier is sensitive to a current passing through a resistor of 20 megaohms.
The above and other advantages is achieved by the device of the invention which consists of an automatic trap for catching cockroach, comprising a box defining a cockroach collecting cavity and an upper surface with a trap opening, at least two separate coplanar plates being provided to close said trap opening in a close position, each plate having an electrical conducting portion connected to a control circuit which, in turn, is connected to a driving mechanism capable of being actuated to move the plates away from each other into an open position for uncovering the trap opening and providing access to the cockroach collecting cavity, whereby when a cockroach simultaneously touches the electrical conducting portions of the plates, said portions are put into electrical contact to each other because of the conductivity provided by the cockroach body, so that the driving mechanism is excited by the control circuit to move the plates to their open position.
The box includes a cap removably fixed onto the upper surface of the box for covering the plates and the driving mechanism, and defining an access with a roof for guiding the cockroach to a bait located under the cap, for attracting the cockroach.